Vitamins and Minerals are essential to health, and most must be supplied by food. Deficiencies are still worldwide killers, either directly or by reducing resistance to other illnesses. In developed countries, where such a variety of food is available, it is hard to see why anyone should lack nutrients. But surveys show that a substantial proportion of people are on or under the borderline of safety, mainly because they eat badly balanced diets.

A less active lifestyle means less food is needed, making it more difficult to obtain all the necessary nutrients, especially if people consume substantial amounts of sugary foods and alcohol, which supply almost no vitamins or minerals. The few calories eaten, the more important it is that almost every calorie carries with it some vitamins and minerals. Some people have a higher-than-average need for one or more nutrients.

More of a vitamin is not always better, but we now know that for some vitamins, a higher intake can benefit people vitamins, a higher intake can benefit people who show no signs of being deficient. For many vitamins, a higher intake can benefit people who show no signs of being deficient. For many vitamins, we can aim for optimum levels.

THE NUTRIENTS WE NEED
Vitamins We Can Store vitamins A, D, E, and B12 can be stored in our bodies for a considerable time. Stores protect us against short-term shortages. For example, plentiful vitamin D, obtained from sunlight on our skin in summer, helps maintain our supply the following winter. But storage also means that body levels can build up and, when eaten in animal foods, even moderately excessive amounts of vitamins A and D produce ill effects. Although the body also produces vitamin A from carotenes in vegetables and fruit, eating these in large amounts does not cause vitamin a excess, nor does an excess of vitamin D result from exposure to sunlight.

In developed countries, shortages of fat-soluble vitamins A,D,E (and K, which is little stored by the body) are mainly due to poor food choice, or for vitamin D, little time spent outdoors. Some people are at risk because they absorb fat poorly, through illness or as a side effect of medication, such as cholesterol-lowering drugs or regular use of laxatives. Some vitamin A and vitamin E in food is lost due to exposure to air in storage, and strong heat during cooking.

Fat-soluble vitamins need not come from high-fat foods: there are good low-fat sources for each one.

Vitamins We Barely Store
The B complex vitamins and vitamins C and K are little stored by the body, so daily intake is important, although the body manufacturers much of the vitamin K it needs. Contact with water will wash some of these vitamins out of food - for example, in canning, soaking, or when cooking in lots of water. Food refining, exposure of cut surfaces to air and light, and prolonged heat also cause major losses. This means that they risk of deficiency is highest among people who rely on processed or overcooked food. Poor food choices and some medications are also hazards. In illness or at other times of stress, the body may benefit from higher levels of the vitamins that we barely store. B vitamins have related functions, so if you are taking a supplement, take all the B complex vitamins. To retain the maximum amount of these vitamins in food.

Minerals
Some 15 minerals are known to be essential to human health, with a few others still under investigation. The exact amount of minerals we need to eat is even less easy to define that for vitamins because, for most minerals, the amount we absorb varies considerably according to the foods that we eat them in. we absorb some minerals less efficiently from goods high in fiber- especially when they also contain phytic acid. This is not a reason to avoid fiber, just to avoid an excess.

Certain minerals can be harmful even in moderately excessive amounts. For iron, there seems to be quite a narrow "good" body level, which is high enough to avoid the harm done by shortage, but low enough not to risk iron pro-oxidant activity, which may encourage the formation of fee radicals, see Anti oxidants, p.21. A very large amount of one mineral may reduce the amount that the body can absorb of another. Such problems are unlikely if we obtain minerals from food rather than from supplements containing much larger amounts.

VITAMINS

VITAMINS

MINERALS